Overview#

The log module provides structured logging: the five levels trace/debug/info/warn/error, dispatched by the backend logPlugin (translated from tauri-plugin-log, P21 v2) to multiple targets: stdout / stderr / file (with rotation) / webview. The frontend can emit logs directly (logger.*), subscribe to backend-pushed records with attachConsole (the webview target), or attach a pure-frontend sink with attachLogger (receives only the log* calls made by this page).

import { logger, attachConsole, attachLogger } from "@zturnlibs/ztron-api/log";
import type { LogLevel, LogSink } from "@zturnlibs/ztron-api/log";

Permissions & Scope#

The plugin is constructed with logPlugin(options):

There is a single permission log:default covering all 8 commands — what the hello example declares. Note that the pipe-carrying command names (plugin:log|__listener) ride the addPluginListener contract rather than named events — named event names reject |.

Example#

Backend registration: three targets + keepOne rotation + a 400-byte cap (so the spike's 12 pressure lines force several rotations). From examples/hello/src/main.ts (comments kept, excerpt elided):

.plugin(
  logPlugin({
    level: "trace",
    targets: ["stdout", "file", "webview"],
    rotationStrategy: "keepOne",
    // Small cap so the spike's 12 pressure lines force several rotations.
    maxFileSize: 400,
  }),
)

Frontend direct logging + attachConsole on the webview target. From examples/hello/frontend/src/main.ts (the anchors LOG_OK and LOG_WEBVIEW_OK are its real run outputs; comments kept, excerpt elided):

// 5e. log plugin
await logger.info("spike: log plugin test from frontend");
report("LOG_OK");

// 13. log plugin v2: webview target round trip via attachConsole, ...
let logEcho: string | null = null;
const unlistenLog = await attachConsole({
  logger: (m) => {
    if (m.includes("spike-log-webview")) logEcho = m;
  },
});
await invoke("plugin:log|info", { message: "spike-log-webview" });

Rotation verification: the log files sit outside the fs scope (the log plugin itself owns that directory), so hello reads the sizes of the current file and the .old backup through the trusted backend command m3:log-rotation; LOG_ROTATE_OK:420->242 is its real run output (keepOne leaves at most .log + .log.old; hello also clears the previous run's stale log files at startup to keep the rotation asserts deterministic).

Commands#

plugin:log|* totals 8 commands:

Full list in the Commands Reference and the API symbol reference.

Applicable version: ztron 0.3.1